Manchester Conditioning Update 11

NO OYSTERS DIED!

Between the new buckets, increased flow, lower temperature and live algae, something is making the oysters happy. The one oyster from Heat Shock B we counted as dead but still weren’t sure about was gaping a lot and did not close its shell at all this morning. We were correct in our assessment that it was dead on Tuesday. But no additional deaths!

I checked the buckets and they really weren’t dirty. I didn’t want to rinse the oysters off with freshwater and accidentally trigger spawning, so I just left the buckets as is. I opened up the Heat Shock B oyster and 2 additional ones from Full Amb B to examine gonad maturation. I wanted to make sure the oysters didn’t reabsorb their gonad in the colder water conditions.

Table 1. Revised oyster counts in each tank, as of July 27.

Tag Label

A

B

Total

1

3

7

10

2

5

8

13

3

2

6

8

4

2

7

9

5

6

8

14

6

4

8

12

Heat Shock

3

4

7

Full Amb

0

4

4

Spare

1

3

4

Total

26

55

81

The Heat Shock B oyster was pretty ripe!

Figure 1. Heat Shock B oyster gonad.

Figure 2. Heat Shock B oyster gametes. These are sperm.

The first one I opened from Full Amb B was pretty unripe. There was a small section that was starting to get milky, but really nothing spectacular. This made me nervous since the gonad was pretty large, just underdeveloped. I wasn’t sure if the gonad was milky previously and the oyster had reabsorbed in two days.

Figure 3. Unripe Full Amb B oyster gonad.

Nervously, I opened up another Full Amb B oyster. This gonad was nice and milky, so I’m not worried about gonad maturity for spawn!

Figures 4-5. Ripe Full Amb B oyster gonad.

If the oysters continue surviving until Saturday and there’s a 50/50 sex ratio, I will have 72 crosses total. There aren’t enough five gallon or two gallon buckets to fertilize all crosses in the same container, so this is something I need to discuss with Steven. There definitely are enough tripours if we choose to fertilize in tripours with airstones.